The appellant, a West Virginia corporation, brought in the circuit court of the United States for the district of Idaho, this bill in equity against Boise City, a municipal corporation. There was a demurrer to the bill, which, upon consideration of the merits of the case set forth therein, was sustained by the judge of the circuit court, and the bill dismissed. The company appealed directly to this court. The facts set forth in the bill and exhibits, and the relief and grounds of relief claimed, so far as necessary to develop the point decided, may conveniently be stated in narrative form.

2

The company was incorporated for and is engaged in supplying the city and its inhabitants with water for municipal and domestic purposes. It had acquired the property, franchises, rights, and privileges of certain individuals and corporations, who had been, from time to time, granted by ordinance of the city the privilege of laying and maintaining pipes in the streets and supplying through them water for municipal and domestic uses. The company conducted its business by virtue of these ordinances, and has invested large sums of money. The ordinances need not be set forth in detail, and it is enough to say that the company contends that they are franchises for a term of not less than fifty years, and constitute a contract inconsistent with the license fee or tax hereafter referred to, while the city contends that they are mere permissions, revocable at any time. The rates are fixed by commissioners, acting under the authority of a law of the state, and are to remain in force three years from the date of their establishment. After the fixing of the rates, and before the expiration of the three years, on the 31st day of May, 1906, the city enacted an ordinance requiring that the company 'hereafter pay to said Boise City, on the first day of each and every month, a monthly license of $300, for the privilege granted . . . to lay and repair water pipes in the streets and alleys of said city.' The ordinance then made a demand for the monthly payment of said license, and directed the city clerk to notify the company of the requirements of the ordinance.

3

The main object of the bill is to obtain an injunction against the enforcement of this ordinance, upon the grounds: (1) That other corporations, associations, and individuals using the streets and alleys of the city for various purposes are not required to pay a license, and therefore there was, by the ordinance, a denial of the equal protection of the laws; (2) that the city, in pursuance of its claim that the ordinances grant only a revocable permission to occupy the streets, threatens and intends to impose further burdens and assessments, and threatens to remove the pipes and the works from the city; (3) that the city has presented monthly bills and has brought an action at law in the state court to recover the amount alleged to be due on account of the license fee imposed, and that there is therefore danger of a multiplicity of suits; (4) that the ordinance has cast a cloud upon the company's franchises and right to supply water to the city and its inhabitants, and thereby depreciated the value of the company's property, impaired its credit, embarrassed its business, and confiscated its property; (5) that the ordinance impairs the obligation of the contract made by the ordinances granting the rights, privileges, and franchises; (6) that the enforcement of the ordinance would deprive the company of its property without due process of law and abridge its privileges and immunities granted by the 14th Amendment; (7) and that the ordinance violates the Constitution and laws of the state.

4

A subordinate object of the bill is to recover from the city certain amounts due on account of water supplied to fire hydrants, which the city declines to pay, disputing its liability so to do.

5

The decree of the court below, dismissing the bill, proceeded upon a consideration of the merits of the controversy between the parties. We do not enter upon that subject, because there is a deeper question which seems to us decisive of the case. That question is whether the plaintiff is entitled, on the allegations of its bill, to relief in equity in the Federal courts.

6

It is obvious that the rights of which the company seeks to avail itself are rights cognizable in a court of law, and not rights created only by the principles of equity. The sum of the company's contentions is that the imposition of the license fee was illegal, unconstitutional, and void. All these contentions are open in a court of law. It is a guiding rule in equity that, in such a case, it will not interpose where there is a plain, adequate, and complete remedy at law. This rule at an early date was crystallized into statute form by the 16th section of the judiciary act [1 Stat. at L. 82, chap. 20] (Rev. Stat. § 723, U. S. Comp. Stat. 1901, p. 583), which, if it has no other effect, emphasizes the rule and presses it upon the attention of courts. New York Guaranty & I. Co. v. Memphis Water Co. 107 U. S. 205, 214, 27 L. ed. 484, 487, 2 Sup. Ct. Rep. 279. It is so well settled and has so often been acted upon that no authority need be cited in its support, though it must not be forgotten that the legal remedy must be as complete, practicable, and efficient as that which equity could afford. Walla Walla v. Walla Walla Water Co. 172 U. S. 1, 11, 43 L. ed. 341, 346, 19 Sup. Ct. Rep. 77.

7

A notable application of the rule in the courts of the United States has been to cases where a demand has been made to enjoin the collection of taxes or other impositions made by state authority, upon the ground that they are illegal or unconstitutional. The decisions of the state courts in cases of this kind are in conflict, and we need not examine them. It is a mere matter of choice of convenient remedy for a state to permit its courts to enjoin the collection of a state tax, because it is illegal or unconstitutional. Very different considerations arise where courts of a different, though paramount, sovereignty, interpose in the same manner and for the same reasons. An examination of the decisions of this court shows that a proper reluctance to interfere by prevention with the fiscal operations of the state governments has caused it to refrain from so doing in all cases where the Federal rights of the persons could otherwise be preserved unimpaired. It has been held uniformly that the illegality or unconstitutionality of a state or municipal tax or imposition is not of itself a ground for equitable relief in the courts of the United States. In such a case the aggrieved party is left to his remedy at law, when that remedy is as complete, practicable, and efficient as the remedy in equity. And the rule applies as well where the right asserted is by way of defense. Phoenix Mut. L. Ins. Co. v. Bailey, 13 Wall. 616, 623, 20 L. ed. 501, 503.

8

In order to give equity jurisdiction, there must be shown, in addition to the illegality or unconstitutionality of the tax or imposition, other circumstances bringing the case under some recognized head of equity jurisdiction, before the remedy by injunction can be awarded. The leading case on the subject is Dows v. Chicago, 11 Wall. 108, 20 L. ed. 65. In that case the plaintiff sought to enjoin the collection of a tax levied upon shares of the capital stock of a national bank on the ground that the levy was unconstitutional under the state law, and that the property was not within the jurisdiction of the state. This court declined to pass upon the validity of the tax, saying, through Mr. Justice Field (p. 109):

9

'The illegality of the tax and the threatened sale of the shares for its payment constitute of themselves alone no ground for such interposition. There must be some special circumstances attending a threatened injury of this kind, distinguishing it from a common trespass, and bringing the case under some recognized head of equity jurisdiction before the preventive remedy of injunction can be invoked. It is upon taxation that the several states chiefly rely to obtain the means to carry on their respective governments, and it is of the utmost importance to all of them that the modes adopted to enforce the taxes levied should be interfered with as little as possible.

10

* * * * *

11

'No court of equity will, therefore, allow its injunction to issue to restrain their action, except where it may be necessary to protect the rights of the citizen whose property is taxed, and he has no adequate remedy by the ordinary processes of the law. It must appear that the enforcement of the tax would lead to a multiplicity of suits, or produce irreparable injury, or, where the property is real estate, throw a cloud upon the title of the complainant, before the aid of a court of equity can be invoked.'

In the case last cited, Mr. Chief Justice Fuller made the following important observation (p. 274):

14

'It is quite possible that, in cases of this sort, the validity of a law may be more conveniently tested by the party denying it by a bill in equity than by an action at law; but considerations of that character, while they may explain, do not justify, resort to that mode of proceeding.'

15

In Shelton v. Platt, 139 U. S. 591, 35 L. ed. 273, 11 Sup. Ct. Rep. 646, a bill was filed in the circuit court of the United States to restrain the collection of a license tax imposed by the state of Tennessee on the United States Express Company, upon the ground that it was unconstitutional. The bill alleged that the property of the company was employed in interstate commerce, and was necessary to the conduct of it, and that if it were seized by the sheriff it would greatly embarrass the company in the conduct of its interstate business, subject it to heavy damage, and the public to great loss and inconvenience, and that the company was without adequate remedy at law. A plea alleged that the only remedy under the laws of the state was to pay the taxes under protest and bring suit to recover them back. The plaintiff had an injunction from the lower court. This court reversed the decree upon appeal, upon the ground that the remedy in equity would not lie merely because the tax was unconstitutional, unless there were allegations in the bill otherwise bringing the case within some acknowledged head of equity jurisdiction, and that the allegations of the bill were not sufficient to do this. This case was followed in Allen v. Pullman's Palace Car Co. 139 U. S. 658, 35 L. ed. 303, 11 Sup. Ct. Rep. 682, and in Pacific Exp. Co. v. Seibert, 142 U. S. 339, 35 L. ed. 1035, 3 Inters. Com. Rep. 810, 12 Sup. Ct. Rep. 250, where a tax was alleged to be unconstitutional because imposed upon interstate commerce, because it denied to the taxpayer the equal protection of the laws, and because it was void for repugnancy to the Constitution of the state.

16

A brief reference to some cases cited by the company, in which this court has asserted the authority of equity to interfere, will define the rule quite as well as the cases in which the court has declined to exercise the power of injunction. In Walla Walla v. Walla Walla Water Co. supra, the city was about to construct, in violation of its contract, a competing water plant, and the resulting damage to the company would have been irreparable. The same conditions existed in Vicksburg Waterworks Co. v. Vicksburg, 185 U. S. 65, 46 L. ed. 808, 22 Sup. Ct. Rep. 585. See same case, 202 U. S. 453, 50 L. ed. 1102, 26 Sup. Ct. Rep. 660, 6 A. & E. Ann. Cas. 253. In Detroit v. Detroit Citizens' Street R. Co. 184 U. S. 368, 46 L. ed. 592, 22 Sup. Ct. Rep. 410, a schedule of rates for transportation of passengers was fixed in violation of the contract rights of the company, and possible suits would be limited only by the number of passengers. The same condition existed in Cleveland v. Cleveland City R. Co. 194 U. S. 517, 48 L. ed. 1102, 24 Sup. Ct. Rep. 756; and see Ex parte Young, 209 U. S. 123, 52 L. ed. 714, 13 L.R.A.(N.S.) 932, 28 Sup. Ct. Rep. 441, where the grounds of the jurisdiction in equity in rate cases are fully set forth and discussed. In Ogden City v. Armstrong, 168 U. S. 224, 42 L. ed. 444, 18 Sup. Ct. Rep. 98, not only was there danger of a multiplicity of suits, but the tax there in question was a lien upon realty and a cloud on the title.

17

It is safe to say that no case can be found where this court has deliberately approved the issuance of an injunction against the enforcement of an ordinance resting on state authority, merely because it was illegal or unconstitutional, unless further circumstances were shown which brought the case within some clear ground of equity jurisdiction.

18

These decisions make it clear that an injunction ought not to be granted unless the bill, besides alleging illegality and unconstitutionality of the ordinance imposing the license fee, sets forth other circumstances which bring the case within some acknowledged head of equity jurisdiction. The only suggestions of this kind which the bill presents are that the enforcement of the ordinance will lead to irreparable injury, to multiplicity of suits, and cast a cloud upon company's title to its franchises.

19

But there is nothing in the bill which leads us to suppose that any of these results would be brought about by leaving the company to its defense at law. If the city had taken any steps indicating a purpose to remove the pipes and works of the company from the streets of the city, and to deny it the right to continue its business, there would be clear reason for the interposition of a court of equity, for if that were done illegally of unconstitutionally an injury would be inflicted for which the law could afford no adequate remedy. In such a case it would be the plain duty of a court of equity to arrest the destructive steps until their legality or constitutionality could be determined. Such a course would be for the best interests of both parties.

20

It is true that the bill contains a vague allegation that the city has threatened to remove the company's pipes and works from the city, but no facts whatever are alleged showing such a threat. The city does not speak except by its council, and nothing has been said or done by them in this direction. On the contrary, the imposition of the license fee and the bringing of a suit for its recovery contemplate continuance, and not restraint, of the business of the company.

21

Nor do we think that there is any danger of a multiplicity of suits in the sense that would authorize the issuance of an injunction. One suit only has been brought, and that by direction of the city council. It remains pending, and when it reaches judgment it will determine finally every question in dispute between the parties. There is no need of any other suit except to prevent the running of the statute of limitations, and nothing to indicate that any will be brought. Where the multiplicity of suits to be feared consists in repetitions of suits by the same person against the plaintiff for causes of action arising out of the same facts and legal principles, a court of equity ought not to interfere upon that ground unless it is clearly necessary to protect the plaintiff from continued and vexatious litigation. Something more is required than the beginning of a single action with an honest purpose to settle the rights of the parties. 1 Pom. Eq. Jur. 3d ed. § 254. Perhaps it might be necessary to await the final decision of one action at law (see, for analogies, Sharon v. Tucker, 144 U. S. 533, 36 L. ed. 532, 12 Sup. Ct. Rep. 720; Boston & M. Consol. Copper & S. Min. Co. v. Montana Ore Purchasing Co. 188 U. S. 632, 47 L. ed. 626, 23 Sup. Ct. Rep. 434), but that we need not decide.

22

Nor do we think that the ordinance casts a cloud upon the title of the company to its franchises. It is not a lien upon them or upon any other property of the company. The city's only remedy is that which it has employed,—an action at law for the collection of the license fee. The plaintiff's real point here is not that the ordinance imposing a license fee casts a cloud upon its title, but that the reason alleged to have induced the ordinance, namely, the city's claim that the company has no more than a mere permission to occupy the streets, unfavorably affects its property and impairs its credit. But we cannot restrain a belief or an expression of it, and are not asked to. We are asked only to restrain an ordinance which in no way fixes a lien or cloud upon the plaintiff's title. It is possible that the ordinance imposing the license fee could be sustained without passing upon the nature of the company's tenure of its privileges. On the other hand, it might be condemned without regard to that consideration.

23

Here is a case where every possible defense to the collection of the license fee which has been suggested by the company is available to it in the action at law pending in the courts of the state of Idaho, and there is no reason whatever shown why the law should not take its course. Presumably, the company, on the ground of diversity of citizenship, might have removed the case from the state court to the circuit court of the United States, if the attempt had been seasonably made. If, however, the litigation continues up to the court of final resort of the state of Idaho, and all claims under the Constitution of the United States are seasonably and properly made in the state courts, and are denied, then the company would be entitled to a review by this court of the judgment of the state court.

24

The attempt to recover the hydrant rentals is so clearly a matter for a court of law that nothing need be said of it.

25

The circuit court dismissed the bill for entirely different reasons than those which have influenced us. We neither approve nor disapprove those reasons, nor intimate any opinion whatever upon the questions passed on by the circuit court. It would be superfluous formalism to reverse the decree of the court below and remand the case to that court, with instructions to dismiss the bill for the reasons given in this opinion, for that court has already dismissed the bill. Therefore, the decree of the court below is affirmed.